JPS59172963A - Rectification compensating device of dc electric machine - Google Patents

Abstract

PURPOSE:To prevent the generation of sparks at the outlet and inlet sides of a brush by regulating the current of an interpose auxiliary winding so that a load shaft of an armature current is moved to the vcinity of the lower limit of a sparkless zone. CONSTITUTION:When a load is small or when a rotor is stopped, it is detected by an operation setter 21 to open an analog switch 22, thereby stopping an input of a signal to a gate signal generator 16. Thus, the generator 16 does not operated, and no current flows to an auxiliary winding 7. When a rotor rotates and a load is applied, the generator 16 and a current controller 17 control the current of the winding 7 along the pattern generated from a pattern signal generator 20 In this manner, the load shaft of the armature current is set to the vicinity of the lower limit of the sparkless zone.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a rectification compensation device for a DC machine such as a motor or a generator equipped with a commutator and brushes, and particularly to a commutator compensation device for adjusting a commutator magnetomotive force. Concerning things with windings.

[Background of the invention]

A direct current machine has a phenomenon in which a sparkless zone moves depending on the rotational speed, and if the amount of movement of this sparkless zone is large, it becomes impossible to operate with sparkless rectification. As a countermeasure for this, conventionally,
The means shown in FIGS. 3 to 3 are employed.

That is, Fig. 1 shows the main parts of a DC machine, where 1 is a yoke, 2 is a field core, 3 is a field winding, 4 is a compensation winding, 5 is a commutator core, and 6 is a compensation winding. 7 is a pole winding, 8 is an armature core, 9 is a slot, and 10 is an armature winding. When supplied with current, the commutator winding 6 magnetizes the commutator core 5, and supplies commutator magnetic flux for rectification compensation to the electric subwinding 10 via the exit gap. The commutator auxiliary winding 7 is wound differentially with respect to the commutator winding 6, and adjusts the amount of commutator magnetic flux for rectification compensation by the commutator winding 6.

Figures 2(a) and 2(b) show how the spark-free zone moves as the rotational speed changes in a DC machine. Figure (a) shows the no-spark zone (shaded area) when operating at low rotational speed.

A is the upper limit and B is the lower limit. Since the center of the non-spark zone is on the load axis 0-P line of the armature current, the DC machine is non-spark rectified. Figure (b) shows the no-spark zone (shaded area) when operating at a high rotation speed.

In this case, the center of the no-spark zone is displaced from the load axis 0-P line, so if the armature current is higher than the intersection point C between the upper limit A of the no-spark zone and the load axis O-P, sparks will be generated from the brushes. occurs, and spark-free commutation cannot be obtained. For this reason, a general DC machine adjusts the interpole magnetomotive force by controlling the amount of current supplied to the interpole auxiliary winding a7 according to the rotational speed and armature current, and thereby adjusts the load axis as shown in the figure (b). 0-Pla to achieve sparkless rectification.

FIG. 3 shows a block diagram of a circuit that performs the above control. In the figure, 3 is a field winding, 4 is a compensation winding, 6 is a commutator winding, 7 is a commutator auxiliary winding, 11 is a commutator, 12 is a brush, 13 is a rotation speed detector, and 14 is a 15 is a multiplier, 16 is a gate signal generator, 17 is a current control circuit, 18 is a smoothing reactor, and 19 is a DC power supply. In other words, in this circuit, the outputs Vn and Vi of the rotation speed detector 13 and the armature current detector 14 are input to the multiplier 15, the output Ve of the multiplier 15 is input to the gate signal generator 16, Current control circuit 1 by the output of 16
The current ip supplied from the external DC power supply 19 to the interpolation auxiliary winding 7 is adjusted by controlling the switching frequency, conduction rate, etc. of the switching elements in the interpolation auxiliary winding 7. Note that the smoothing reactor 18 is for reducing the pulsation rate of the current flowing through the commutator auxiliary winding 7.

With the above configuration, the current ip in the copole auxiliary winding 7 increases in accordance with the increase in rotation speed and armature current, and therefore the copole magnetomotive force changes, as shown in Fig. 2 (b). The load axis will now move on the 0-P1 line centered on the no-spark zone. As a result, the DC machine can be operated with sparkless rectification.

By the way, in general, in @flow machines, the generation of sparks on the inlet side of the brush is rarely a problem, and the generation of sparks has only been considered a problem on the outlet side of the brush. For this reason, even in the conventional rectification compensation system as described above, the conditions for non-sparking rectification are determined by focusing on the outlet side of the brush. Recently, however, with the trend toward downsizing of DC machines, factors that make rectification difficult have increased, such as higher armature voltages, higher rotational speeds, and larger magnetic loads. Therefore, the generation of sparks has become a problem not only on the outlet side of the brush but also on the inlet side.However, in the conventional rectification compensation method, as mentioned above, the conditions for spark-free commutation are determined by focusing on the outlet side of the brush. Therefore, although it is possible to prevent sparks from occurring on the outlet side of the brush, it is not possible to prevent sparks from occurring on the inlet side of the brush.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rectification compensator for a DC machine that eliminates the above-mentioned drawbacks of the prior art and can prevent sparks from occurring not only on the outlet side of the brush but also on the inlet side.

[Summary of the invention]

In order to achieve the above object, the present invention comprises a rotor having an armature and a commutator, a positive pole including a field core and a field winding, a commutator core, a commutator winding, and a commutator auxiliary winding. In the rectification compensator of the 5 iM flow machine, the current of the commutating pole auxiliary winding is The present invention is characterized in that an adjustment means is provided for adjusting the load axis of the armature current to be near the lower limit of the no-spark zone.

The reason for adjusting the current in the interpolation auxiliary winding as described above is as follows.

Figure 4 shows the pile value er of the reactance voltage induced in the rectifier coil during the rectification period (in the case of linear rectification) and the rectification electromotive force induced in the rectifier coil by the commutator magnetic flux for rectification compensation created by the commutator. Shows the shape and size of ec. eel is the rectified electromotive force at the upper limit of the spark-free zone (when the interpolation magnetomotive force is increased), which is set depending on the presence or absence of sparks on the brush outlet side, and e(2
is the rectified electromotive force at the lower limit of the same no-spark zone (when the interpolation magnetomotive force is reduced). Tl is the rectification start side, and T2 is the rectification end side. Focusing on the rectification leakage side T1, over-rectification occurs at the upper limit of the spark-free zone, and the rectified electromotive force ec1 is thicker than the reactance voltage peak value er, so sparks are generated on the brush inlet side.On the other hand, At the lower limit of the no-spark zone, there is insufficient rectification, and since the rectified electromotive force ec2 almost matches the pile value ef of the reactance voltage, no sparks are generated on the brush inlet side.

FIG. 5 shows the occurrence of sparks on the brush inlet side at the upper and lower limits of the spark-free zone set with the brush outlet side as a reference. SPl indicates the number of sparks on the brush inlet side when the load axis of the armature current is set at the upper limit of the no-spark zone (No. 1 means no spark, No. 2 or higher means sparks occur). In this case, sparks are always generated on the brush inlet side, and the number of sparks tends to increase as the armature current increases.

On the other hand, SF3 indicates the number of sparks on the brush inlet side when the load axis of the armature current is set to the lower limit of the no-spark zone, and in this case, no sparks occur on the brush inlet side. As explained in Fig. 4, at the lower limit of the no-spark zone, this is the sum of the rectified electromotive force ec2 and the reactance voltage e.
This is consistent with the fact that r is almost the same.

From the above study results, as shown in Fig. 6, compensation should be made so that the load axis of the armature current is between the upper limit A and lower limit B of the non-sparking zone, and on the 02-P2 line near the lower limit B. It can be seen that by adjusting the polar magnetomotive force, rectification without generating sparks can be performed not only on the outlet side of the brush but also on the inlet side. The copole magnetomotive force can be adjusted by adjusting the current in the copole auxiliary winding.

[Embodiments of the invention]

FIG. 7 is a block circuit diagram of a rectification compensator for a DC machine according to an embodiment of the present invention. In this figure, parts corresponding to those in FIG. 3 are given the same reference numerals as in FIG. 3. Newly provided components are a pattern signal generation circuit 20, an operation setting circuit 21, and an analog switch 22.

Details of the pattern signal generation circuit 20 are shown in No. 813\1. In the figure, 23a, 23b, . . . are analog switches, and 24a, 24b, . . . are pattern generators.

The pattern generators 24a, 24b, . . . have rotational speeds ■. A pattern of voltages p proportional to the armature current Vi is output depending on the magnitude of the voltage. That is, the pattern signal generation circuit 20 detects the detected value Vn of the rotational speed detector 13.
Analog switches 23a, 23b...
. . operate one of the pattern generators 24a, 24b, . Outputs a voltage p proportional to the value Vi.

The operation setting circuit 21 functions to open the contacts of the analog switch 22 by detecting when the load is small (for example, when the armature current is zero) or when the load is stopped.

Next, the operation of this device will be explained.

First, if the load is small or the N trochanter is stopped, spark generation is not a problem, so the operation setting circuit 21 detects it, turns off the analog switch 22, and sends the signal to the gate signal generator 16. Therefore, the gate signal generator 16 does not operate, and no current flows through the interpolation auxiliary winding 7.

The copole magnetomotive force is adjusted by the current in the copole auxiliary winding 7 when the rotor is rotating and a load is applied. When the detected value ■n of the rotational speed is input, the pattern signal generation circuit 20 outputs the voltage ■p for the detected armature current value ■n in a pattern corresponding thereto as described above. For example, when the rotational speed is low, the pattern output is as shown in FIG. 9(a). That is, when the rotation speed is low, when the signal voltage of ■l is output from the pattern signal generation circuit 20, the load axis of the armature current is set to the lower limit of the non-sparking zone by the magnetomotive force of the interpolation auxiliary winding 7. If so, the pattern signal generation circuit 20 generates a pattern voltage v that is slightly smaller than that.
Output p. As a result, the gate signal generator 16 and current control circuit 17 control the current in the interpolation auxiliary winding 7 according to this pattern, so the load axis of the armature current is the ]0th factor (
As shown in b), 03-P3 is near the lower limit of the no-spark zone.
Set on the line.

Therefore, spark-free rectification can be performed not only on the outlet side of the brush but also on the inlet side. Further, when the rotational speed is high, the output of the pattern signal generation circuit 20 becomes a pattern like the ninth meat (b), for example.

That is, when the rotation speed is high, when the signal voltage of V2 is output from the pattern signal generation circuit 20, the load axis of the armature current is set to the lower limit of the non-sparking zone due to the magnetomotive force of the interpolation auxiliary winding 7. In this case, the pattern signal generation circuit 20 outputs a pattern voltage Vp that is slightly smaller than that. As a result, the current in the commutator auxiliary winding 7 flows along this pattern to the open side j
Therefore, the load axis of the armature current is set on the 04-P4 line, which is near the lower limit of the spark-free zone, as shown in FIG. 10(b), and sparks can be prevented from occurring even on the brush inlet side.

FIG. 11 is a block circuit diagram showing another embodiment of the present invention. In this figure, parts corresponding to those in FIG. 3 are given the same reference numerals as in FIG. 3. The newly established one is code 21.
22 analog switches, 25 detection brushes, 26 isolation amplifiers, 27 function generators, and 28 adders.

The operation setting circuit 21 and analog switch 22 are the same as those described in the embodiment of FIG.

The detection brush 25 is installed on the outlet side of the brush 12 and is in sliding contact with the same surface of the commutator 110 as the brush 12, and detects the voltage vb (hereinafter referred to as , brush voltage).

The function generator 27 adjusts the brush voltage to ± the spark generation limit voltage.
If the voltage is suppressed to within 3V, sparkless rectification will occur, so the command value s is set to a positive 2.5 to 2.8V (near the lower limit of the no-spark zone), and as shown in Figure 12, the detected value is Brush voltage V
When b is within the range of the command value ■s, the output is zero,
When it is lower than the command value Vs, a positive signal voltage Vkt proportional to the magnitude thereof is outputted, and when it is higher than the command value Vs, a negative signal voltage Vk2 proportional to the magnitude is outputted. negative signal voltage V
k2 has a larger slope than the positive signal voltage Vkt.

The adder 28 adds the output of the multiplier 15 and the output of the function generator 27, and inputs the result to the gate signal generator 16.

Next, the operation of this device will be explained.

Assume that the DC machine is rotating at a low rotational speed and is under load. Therefore, the multiplier 15 receives the detected value Vi of the armature current detector 14 and the detected value ■n of the rotational speed detector 13. However, since the multiplier 15 is set not to operate at low rotational speeds, it does not output a signal. On the other hand, the brush voltage vb detected by the detection brush 25 is input to the function generator 27 via the insulation amplifier 26. The detected brush voltage ■b is the command value Vs (
+2.5 to 2.8V), the load axis is near the lower limit of the no-spark zone (+3V), so it can be left as is, but if the brush voltage Vb is smaller than the command value Vs, the function generator 27 inputs a positive signal voltage Vk□ corresponding to its magnitude to the gate signal generator 16 through the adder 28 and the analog switch 22, as shown in FIG.
This causes the current control circuit 17 to operate. As a result, the auxiliary magnetomotive force changes even at low rotational speeds, and Figure 10 @
), the load axis of the armature current moves to the o, -p3 line near the lower limit of the no-spark zone. Therefore, for the reasons mentioned above, it is possible to prevent sparks from occurring on the brush inlet and outlet sides. Furthermore, when no load is applied to the DC machine, the operation setting circuit 21 operates to open the contacts of the analog switch 22, so that no current is supplied to the interpolation auxiliary winding 7.

Next, we will explain the case where the DC machine is rotating at a high rotational speed and is under load. In this case, the multiplier 15 combines the detected value Vi of the armature current and the detected value ■n of the rotational speed.
The gate signal generator 16 and current control circuit 17 operate, and current is supplied to the interpolation auxiliary winding 7.

Since this control is the same as the conventional one, the result is that the load shaft is moved along the O-P line in the center of the non-sparking zone as shown in FIG. 2 (b). In this embodiment, in addition to this, the following control is performed. That is, when the detection voltage Vi of the detection brush 25 is smaller than the command value ■s, the function generator 27
As shown in FIG. 2, a positive signal voltage V k 1 is output.

This signal voltage Vkx is added to the output e of the multiplier 15 in the adder 28, and the added signal voltage V is input to the gate signal generator 16, so the current flowing through the interpolation auxiliary winding 7 increases. do. As a result, the load axis is shown in Figure 10←)
As shown in FIG. 2, the current is moved to the O, -P4 line near the lower limit of the no-spark zone, and it is possible to prevent sparks from occurring on the outlet and inlet sides of the brush. Note that when there is no load, the operation setting circuit 21 operates and no current is supplied to the commutator auxiliary winding #J7.

By the way, when a DC machine is operated, the state of film formation on the brush changes as the operating time passes, and the position of the non-spark zone moves, so that non-spark rectification may become impossible. Honjitsu 5 Martyrs can deal with such phenomena as follows. That is, when the state of film formation on the brush changes and the position of the spark-free zone moves, and the voltage Vb detected by the detection brush 25 becomes positive 2.8 mm or higher, that is, in the spark generation region, the function generator 27 generates a negative signal voltage Vk2 corresponding to the magnitude of 5 as shown in FIG. Moreover, this negative signal voltage Vk2 has a larger rate of change with respect to the brush voltage b than the positive signal voltage vk□, so the degree of decrease in the signal voltage Vo input to the gate signal generator 16 is larger. (As a result, the current in the commutator auxiliary winding 7 increases (decreases), and the load axis is automatically set near the lower limit of the no-spark zone.

According to this embodiment, even if the position of the sparkless zone changes depending on the rotational speed or the state of film formation on the brush,
Since the load axis is always adjusted to be near the lower limit of the spark-free zone, it is possible to prevent sparks from occurring not only on the outlet side of the brush but also on the inlet side. In addition, positioning the load axis near the lower limit of the no-spark zone also means under-commuting, so the main magnetic flux increases due to the armature reaction of the rectifier coil, and the speed rise characteristic that occurs during field weakening can be prevented. There is also an advantage.

〔Effect of the invention〕

As explained above, according to the present invention, the current in the commutator auxiliary winding is adjusted so that the load axis of the armature current is near the lower limit of the non-sparking zone. This has the effect of preventing sparks from occurring even on the inlet side.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing part of the stator and rotor of a DC machine, Figures 2 (a) and (b) are graphs showing the conventional compensation method for movement of the no-spark zone, and Figure 3 is the conventional compensation method. Figure 4 is a graph showing the relationship between the reactance voltage pile up value and the rectified electromotive force during the rectification period, and Figure 5 shows the brush inlet at the upper and lower limits of the non-sparking zone. 6 is a graph showing the preferred setting position of the armature current load axis in the non-sparking zone. FIG. 7 is a rectification compensator for a DC machine according to an embodiment of the present invention. FIG. 8 is a block circuit diagram showing a specific example of the pattern signal generation circuit in the same device, FIGS. 9 (a) and (b) are graphs showing examples of the output of the pattern signal generation circuit, Fig. 10(A) and (A) are graphs showing the position of the load axis of the armature current set by the same output, Fig. 11 is a block circuit diagram showing a device according to another embodiment of the present invention, and Fig. 12 The figure is a graph showing an example of the output of the function generator in the same device. 3...Field winding, 4...Compensation winding, 6
・・・・・・Commuting pole winding, 7・・・・・・Commuting pole auxiliary winding,
10... Armature winding, 11... Commutator, 12... Brush, 13... Rotation speed detector, 14... Armature current detector, 15...
...Multiplier, 16...Gate signal generator,
17... Current control circuit, 20... Pattern signal generation circuit, 21... Operation setting circuit, 2
2...Analog switch, 25...Detection brush, 26...Function generator, 28...
...Adder. 338- 3rd mouth 4th mouth 5th eye 6th hole 7th day 8th buttocks 9th prisoner 10th Ill

Claims (1)

[Claims] ■. A rotor having an armature and a commutator, a field W+'E pole consisting of an iron core and a field winding, a commutator core, a commutator winding, and the commutator % wire. A stator comprising a copole that softens from a differentially wound copole auxiliary winding and a brush, and transmitting and receiving power to and from the armature via the brush and the strainer, A rectification compensator for a DC machine, characterized in that an adjustment means is provided for adjusting the current in the commutating auxiliary winding so that the load axis of the armature current is near the lower limit of the no-spark zone. 2. In the first claim, the adjusting means comprises:
The output signal of the pattern signal generation circuit has a pattern signal generation circuit that selects a preset pattern according to the detected rotational speed value and generates an output signal proportional to the output value of the armature current. A rectification compensation device for a DC machine, characterized in that the current in the interpolation auxiliary winding is adjusted based on. 3. In claim 1, the adjustment means:
Rectification compensation for a DC machine, characterized in that it has a rotational speed detection means, an armature current detection means, and a rectification state detection means, and the current of the commutating pole auxiliary winding is adjusted according to the detected values thereof. Device. 4. The DC machine according to claim 3, wherein the rectification state detection means includes a detection brush that detects a voltage between brush commutator pieces provided near the outlet side of the brush. Rectification compensator. 5. In claim 3, the rectification state detection means includes a detection brush that detects the voltage between the brush commutator pieces on the outlet side of the brush, and a detection brush that detects the voltage between the brush commutator pieces on the outlet side of the brush, and a positive voltage when the detected voltage is less than or equal to a command value; and a function generator that outputs a negative voltage when and an adder for calculating the sum of the outputs of the function generator, and the current in the commutating auxiliary winding is adjusted according to the output of the adder. Device.